There are known optical disc drives, which record and/or reproduce information on an optical disc that is rewritable, such as CD-RW and the like.
Such optical disc drives include: a rotational driving mechanism for rotating a loaded optical disc; an optical pick-up (optical head) which is provided movably in a radial direction with respect to the loaded optical disc for emitting a laser beam to be able to record data (information) on the disc; and an optical pick-up moving mechanism equipped with a sled motor for moving the optical pick-up in the radial direction.
In the optical disc drive having such a function for recording data, it is required to acquire an optimum recording power (writing output of the laser beam) suitable for an inherent property of an optical disc and conditions of the circumstances before actually writing (recording) information onto the optical disc.
Acquiring the optimum recording power is referred to as OPC (Optimum Power Control). An OPC procedure is carried out at a region called as PCA (Power Calibration Area) that is positioned at the innermost region of an optical disc. The PCA is divided into two regions, i.e., a Test Area and a Count Area.
Trial writing is carried out in the Test Area by changing the output level of the laser beam in a stepwise manner, and the count (number of times) of trial writing (the count (number of times) of the OPC procedure) is recorded in the Count Area.
Further, in the case where there is no space to carry out trial writing in the Test Area, the optical disc drive carries out CW erase (Continuous Wave Erase) procedure to erase trial writing data that is recorded in the Test Area.
However, sometimes the trial writing data that is recorded in the Test Area cannot be erased completely by only one CW erase, and if trial writing is carried out in a state where the trial writing data still remains in the Test Area, overwrite procedure is carried out on the portion in which the writing data remains.
In this case, an optimum output level of the laser beam cannot be acquired, and an improper output level of the laser beam may be determined as the optimum recording power.
When recording data is carried out at the improper output level of the laser beam that is determined in the OPC procedure, for example, in the case where the output level of the laser beam is higher than the optimum output level, the optical disc may suffer a significant damage, on the other hand, in the case where the output level of the laser beam is lower than the optimum output level, the recording procedure may be insufficient, thereby being incapable of recording data accurately.
Further, in this case, when the recorded information is reproduced, high-quality signals cannot be obtained.